Len'en Tasouken (Connecting Chain of the Snake Thicket Sword) ~ Earthen Miraculous Sword (連縁蛇叢釼 ～ Earthen Miraculous Sword) is a vertical-scrolling danmakushoot 'em up and the second game of the Len'en Project. It was made by Trick Nostalgie's sole member JynX and released for the Windows operating system. The trial version was released on 12 September, followed by the full version on 18 November 2013 as a free download. It was developed and released concurrently with the first game in the series, Evanescent Existence. The game was made with inspiration from the Touhou Project.

Contents

Like the Touhou Project, game titles in the Len'en Project consist mainly of five Japanese kanji, plus an English sub-title that relates to the main title without necessarily being a translation. In the title, "Tasouken (蛇叢釼)" is the name of the sword that can sever relations. "Earthen Miraculous Sword" also refers to the sword. The Japanese title was originally "鏈縁蛇叢釼", but it was changed to "連縁蛇叢釼" in v1.10 in accordance with Brilliant Pagoda or Haze Castle.

The game has three playable characters, a story mode with 6 stages and an Extra Mode with selectable difficulty – Easy Extra Mode and Extra Mode which can be unlocked by clearing the main game on any difficulty, as well as Absurdly Extra Mode which is only unlocked once the main game is cleared on Unreal difficulty.

The main new gameplay mechanic involves grazing to fill a meter which will allow the player to use a special bomb known as a "flash bomb". Pressing the bomb button while unfocused will release a flash bomb if the meter is full, otherwise it won't do anything.

There is also another mechanic called the "cloud flower gauge", which is represented by a five-petaled flower on the bottom-right of the screen. It fills up by defeating enemies and capturing spell cards, but it depletes when the player dies or bombs. The higher it is, the greater point multiplier will be awarded, and if you finish the game with at least three petals, something special may happen.

The game features original tracks composed by JynX that mimics ZUN's style. Similar to the Touhou Project games, the music room doesn't show the names of all the themes from the first time playing and thus requires to select one theme twice if the player wants to listen to the track. There may be a few melodies in most of the tracks that strongly resembles those from the Touhou Project.

JynX originally spent their time creating convincing, but fake remakes of the PC-98Touhou games (which they still do today). Eventually, they decided to make a completely separate "Touhou-like" series, and thus Len'en was born. They tried to make original resources and styling that tried to mimic the Touhou Project as much as possible. The game is made for Microsoft Windows and DirectX, and it was JynX's first time programming in object-orientedC++, using the DX Library to easily link one into the other. JynX admits that development of Evanescent Existence and Earthen Miraculous Sword was complicated, drawing a lot of drafts for any detail.[1]

A trial version of the game, v0.01a, was first released on 12 September 2013. The initial full version, v1.00a, was released on 18 November 2013 alongside Evanescent Existence. On 2 March 2014, a patch to v1.01a was released, containing unspecified bugfixes. On 14 October 2017, v1.10a of the game was released. This update opened the game's text and image resources to allow for easier translation. It also introduced Suzumi Kuzu as an unlockable fourth player character.